The stacked imaging sections of the target line after PSDM. (a) and (e) The vacuum method imaging results with dominant frequencies of 15 and 20 Hz, respectively. (c) and (g) The 3DIBM imaging results at these frequencies. The second column showing (b), (d), (f), and (h) are enlarged views of the regions within the black dashed boxes in (a), (c), (e), and (g), respectively, highlighting the disparities produced by the two modelling techniques.